Report on the Bacteriology of Water. 1H5 



It was owing to our consciousness of these experimental difficulties 

 that we resolved to confine our own investigations in the first instance 

 to the study of such a pathogenic form as would permit of these 

 difficulties being reduced to a minimum, and to this end we naturally 

 selected the Bacillus anthracis. But in so doing we also had a second 

 object in view, for, inasmuch as the spores of this bacillus are among 

 the hardiest forms of pathogenic organisms, their deportment under 

 any particular conditions is of peculiar interest as exhibiting the limit 

 of endurance which has to be taken into consideration in dealing with 

 pathogenic bacteria. Thus, conditions which are found to be fatal to 

 anthrax spores may in general be assumed to be a fortiori fatal to 

 other pathogenic forms. Again, we have in the case of anthrax the 

 possibility of determining in a much more decisive manner than with 

 other forms the influence which conditions exert on the virulence of 

 the organism. 



The Vitality of Bacillus anthracis and its Spores in Water. 



As indicated in our First Report, this question has already occu- 

 pied the attention of a number of investigators. In some cases the 

 bacilli* free from spores, in other cases sporiferous bacilli, have been 

 employed ; again, in some experiments sterile, and in others un->' 

 sterilised, waters have been used, whilst the temperature at which 

 the waters were maintained during the experiments has also been 

 varied. 



Thus, Wolff lriigel and Riedel (' Arbeiten a. d. Kais. Gesundheits- 

 amte,' vol. 1, 1886, p. 455) introduced the bacilli, which may 

 possibly have contained spores, t as they were taken from a gelatine 

 culture, into sterile water kept at 35° C, and obtained abundant 

 multiplication, whilst when similar bacilli were placed in water at 

 7 — 10° C. their presence was no longer demonstrable by culture after 

 two days, although a few bacilli (or spores) must still have been pre- 

 sent in a virulent condition, as of four mice, each inoculated with 

 J c.c. of the water, one died of anthrax. The water employed in these 

 experiments was primarily the polluted liquid found in the "River 

 Panke at Berlin, although the results were substantially similar when 

 this water was diluted with ten times its volume of distilled water. 

 These investigators made no experiments with unsterilised water. 



* We adopt the following terminology throughout : — Asporogenous means in- 

 capable of developing spores ; sporiferous bacilli are bacilli actually containing 

 spores, whereas vegetative bacilli are bacilli free of spores, though not necessarily 

 incapable of developing them later. 



f Gelatine cultures do not develop spores very rapidly, so that it is by .no means 

 certain that spores were introduced ; however, these observers added so much 

 gelatine that we cannot attach much value to the conclusions. 



TSf 2 



